Brian Stuard carded a flawless opening-round 64 for a one-shot lead as bad weather wreaked havoc at the Zurich Classic of New Orleans.
Stuart was red hot with his putter, holing eight birdies and going bogey-free to set the early pace in wet conditions after play was delayed by almost five hours at TPC Louisiana on Thursday.
The American 33-year-old - yet to win on the PGA Tour - managed to finish his final hole following the length delay, with defending champion Justin Rose among the afternoon group unable to complete their rounds.
After opening with back-to-back birdies, Stuard scored under par at the fourth, seventh and ninth holes, before adding the 10th, 13th and 16th to his tally.
"I feel it's getting closer," Stuart - a two-time runner-up on Tour - told the Golf Channel. "I've been working hard at it and just needed to see some results, and today it was a good one."
South Africa veteran Retief Goosen is a stroke further back following his seven-under-par 65.
J.J. Henry, Geoff Ogilvy, Derek Ernst, Charles Howell III and Patrick Rodgers were among the fortunate players to finish the 18 holes at five under.
Rickie Fowler and Danny Lee are a stroke further back.
World number one Jason Day, meanwhile, is five shots off the pace after faltering late.
Day was flying high until the back nine, where he dropped four shots, closing out his round with back-to-back bogeys for a 69 after a large portion of the day was wiped out by thunderstorms.
Patton Kizzire, Luke List, Jamie Lovemark, Charley Hoffman and David Toms are also three under the card, despite failing to finish their rounds.